"I look at GaGa and I think, 'How does she do it?' I talk to her mom and dad about it. They worry," John told The Guardian.

"She is frail, and she doesn't eat when she should do, and she's a girl, and it's tougher for a girl. She works really hard. She will be in Denmark one night and Saudi Arabia the next. I know how tiny she is and I do worry about her, yes."